Pneumatic tires are made from rubber synthetic elastomeric components some of which are cord reinforced with synthetic textile or steel wire cords.
Typically in passenger or light truck tires the synthetic cords are used in the carcass ply fabric and the wire cords are disposed in the belt structure. Heavy duty truck tires may use steel wired cords in both the carcass ply and the belt structure.
The tire is generally mounted onto a rim secured by a pair of bead reinforcing structures each having a bead core comprised of a coil of steel wires with an elastomeric filler commonly called an apex due in part to its somewhat elongated triangular shape. Sometimes a cord reinforced flipper could be used wrapped about the bead core and the flipper with the bed core and apex components could be pre-assembled to form an intermediate article of manufacture that later could be assembled into a “green” or unvulcanized tire carcass toroidally shaped prior to applying the belt reinforcing structure and tread rubber. Thereafter the entire assembly would be placed in a heated mold and cured.
Typically a tire is formed from long strips of components that are cylindrically wound upon a tire building drum, cut to length and spliced using a lap or butt splice. Thereafter the assembly has the bead cores applied on each end and an apex positioned next to each bead core and then the ply turnup ends are folded over the bead core and apex and then stitched. After which this substantially cylindrical shaped assembly is toroidally shaped by expanding the diameter of the assembly between the beads and the beads are moved towards one another. Thereafter a belt structure and tread are applied and the green tire is then cured in a vulcanizing mold.
These methods of assembly are well known in the building art.
Due to the large number of strip components that are wound onto the building drum to form a tire carcass these strips being cut to length and spliced together at the ends in the manufacture and assembly of a tire means the assembly has to be precisely and tightly controlled to insure that a high quality finished product is produced with uniformity. Each out of place component or over or undersized part or bad splice joint can create a noticeable imbalance or ride disturbance particularly at highway speeds. It is therefore desirable to insure the tires as being manufactured have the strip components made in precisely the right size, positioned properly on assembly, cut to an exact length and properly spliced. Additionally these goals must be accomplished efficiently so the tires are affordable.
To meet these goals it is desirable to automate and in some cases form subassemblies or to make the components at the tire building machine.
The present invention described below provides a unique subassembly used as an intermediate article in the manufacture of a tire and an equally unique method in its manufacture.